doc/examples/easy-ust/sample_component_provider.h

   1 /*
   2  * Copyright (C) 2011-2012  Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   3  * Copyright (C) 2011-2012  Matthew Khouzam <matthew.khouzam@ericsson.com>
   4  *
   5  * Permission is hereby granted, free of charge, to any person obtaining a copy
   6  * of this software and associated documentation files (the "Software"), to deal
   7  * in the Software without restriction, including without limitation the rights
   8  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   9  * copies of the Software, and to permit persons to whom the Software is
  10  * furnished to do so, subject to the following conditions:
  11  *
  12  * The above copyright notice and this permission notice shall be included in
  13  * all copies or substantial portions of the Software.
  14  */
  15
  16 /*
  17  * Sample lttng-ust tracepoint provider.
  18  */
  19
  20 /*
  21  * First part: defines
  22  * We undef a macro before defining it as it can be used in several files.
  23  */
  24
  25 /*
  26  * Must be included before include tracepoint provider
  27  * ex.: project_event
  28  * ex.: project_component_event
  29  *
  30  * Optional company name goes here
  31  * ex.: com_efficios_project_component_event
  32  *
  33  * In this example, "sample" is the project, and "component" is the
  34  * component.
  35  */
  36 #undef TRACEPOINT_PROVIDER
  37 #define TRACEPOINT_PROVIDER sample_component
  38
  39 /*
  40  * include file (this files's name)
  41  */
  42 #undef TRACEPOINT_INCLUDE_FILE
  43 #define TRACEPOINT_INCLUDE_FILE ./sample_component_provider.h
  44
  45 /*
  46  * Add this macro and its matching element to make sure the program
  47  * works in c++.
  48  */
  49 #ifdef __cplusplus
  50 extern "C" {
  51 #endif /* __cplusplus */
  52
  53 /*
  54  * Add this precompiler conditionals to ensure the tracepoint event generation
  55  * can include this file more than once.
  56  */
  57 #if !defined(_SAMPLE_COMPONENT_PROVIDER_H) || defined(TRACEPOINT_HEADER_MULTI_READ)
  58 #define _SAMPLE_COMPONENT_PROVIDER_H
  59 /*
  60  * Add this to allow programs to call "tracepoint(...):
  61  */
  62 #include <lttng/tracepoint.h>
  63
  64 /*
  65  * The following tracepoint event writes a message (c string) into the
  66  * field message of the trace event message in the provider
  67  * sample_component in other words:
  68  *
  69  *    sample_component:message:message = text.
  70  */
  71 TRACEPOINT_EVENT(
  72         /*
  73          * provider name, not a variable but a string starting with a letter
  74          * and containing either letters, numbers or underscores.
  75          * Needs to be the same as TRACEPOINT_PROVIDER
  76          */
  77         sample_component,
  78         /*
  79          * tracepoint name, same format as sample provider. Does not need to be
  80          * declared before. in this case the name is "message"
  81          */
  82         message,
  83         /*
  84          * TP_ARGS macro contains the arguments passed for the tracepoint
  85          * it is in the following format
  86          *              TP_ARGS( type1, name1, type2, name2, ... type10, name10)
  87          * where there can be from zero to ten elements.
  88          * typeN is the datatype, such as int, struct or double **.
  89          * name is the variable name (in "int myInt" the name would be myint)
  90          *              TP_ARGS() is valid to mean no arguments
  91          *              TP_ARGS( void ) is valid too
  92          */
  93         TP_ARGS(char *, text),
  94         /*
  95          * TP_FIELDS describes how to write the fields of the trace event.
  96          * You can use the args here
  97          */
  98         TP_FIELDS(
  99         /*
 100          * The ctf_string macro takes a c string and writes it into a field
 101          * named "message"
 102          */
 103                 ctf_string(message, text)
 104         )
 105 )
 106 /*
 107  * Trace loglevel, shows the level of the trace event. It can be TRACE_EMERG,
 108  * TRACE_ALERT, TRACE_CRIT, TRACE_ERR, TRACE_WARNING, TRACE_INFO or others.
 109  * If this is not set, TRACE_DEFAULT is assumed.
 110  * The first two arguments identify the tracepoint
 111  * See details in <lttng/tracepoint.h> line 347
 112  */
 113 TRACEPOINT_LOGLEVEL(
 114        /*
 115         * The provider name, must be the same as the provider name in the
 116         * TRACEPOINT_EVENT and as TRACEPOINT_PROVIDER above.
 117         */
 118         sample_component,
 119        /*
 120         * The tracepoint name, must be the same as the tracepoint name in the
 121         * TRACEPOINT_EVENT
 122         */
 123         message,
 124        /*
 125         * The tracepoint loglevel. Warning, some levels are abbreviated and
 126         * others are not, please see <lttng/tracepoint.h>
 127         */
 128         TRACE_WARNING)
 129
 130 #endif /* _SAMPLE_COMPONENT_PROVIDER_H */
 131
 132 /*
 133  * Add this after defining the tracepoint events to expand the macros.
 134  */
 135 #include <lttng/tracepoint-event.h>
 136
 137 /*
 138  * Add this macro and its matching element to make sure the program
 139  * works in c++.
 140  */
 141 #ifdef __cplusplus
 142 }
 143 #endif /* __cplusplus */